In a system, measurement data obtained by measuring an object to be measured using one or more portable measuring devices such as vernier calipers are collected in a host system installed at a place apart from the measuring devices so as to perform processing, such as totaling, of the measurement data. In this system, the measurement data in the measuring devices must be transmitted to the host system as accurately and efficiently as possible. A measuring device integrally incorporating a small data processing unit, e.g., a data processing unit constituted by a microcomputer, and a transmitter has been developed as a measuring device for transmitting measurement data in the measuring device to a host system as accurately and quickly as possible. According to such a measuring device having a transmitter, measurement data obtained in a measuring device section is edited by the data processing unit so as to be a transmission data string constituted by a data frame having a predetermined format, and the transmission data string is output by radio transmission using the transmitter. A receiver is incorporated in the host system side. The measurement data included in the data frame of the transmission data string is read by a host computer so as to perform totaling of the measurement data. When the measuring device section is connected to the host system by radio communication in this manner, measurement data can be transmitted to the host system in a real time manner without degrading operation efficiency during a measuring operation even if a portable measuring device, such as a vernier caliper or a micrometer, which is directly held and operated by an operator, is used as the measuring device.
In the measuring device having a transmitter, in which the data processing unit and the transmitted are arranged in the measuring device section in the above manner, however, the following problems are still left unsolved.
The data processing unit and the transmitter for transmitting the transmission data string, which is edited by the data processing unit, by radio transmission upon, e.g., frequency shift keying (FSK) of the transmission data string must be small in size and light in weight so as not to interfere with operability and portability of the measuring device section itself For this reason, the data processing unit and the transmitter are generally constituted by a certain number of IC semiconductor elements, and are housed in a single casing so as to be attached to the measuring device section. However, in the transmitter formed to be small and lightweight in this manner, since a transmission output of a radio wave cannot be set to be very high, an antenna having a relatively large length is required.
If, however, a long, nonflexible antenna such as a rod antenna is attached to the measuring device having a transmitter, the operability of the measuring device section is greatly degraded. In place of the rod antenna, a flexible antenna such as a vinyl-coated wire may be attached to the device. In this case however, since the operator's hands and arms may be tangled with the antenna when the measuring device section is operated, operability of the measuring device section is degraded like the rod antenna.
Consequently, in order to receive a low-power radio wave output from the transmitter attached to the measuring device section, the antenna of the receiver of the host system must be installed near a measurement site. If the receiving antenna is installed excessively near the measuring site, a measuring operation is also interfered.
The present invention has been made in consideration of such a situation, and has as its object to provide a measuring device having a transmitter, which incorporates a transmitter and has an antenna output terminal of the transmitter connected to a casing fixed to a measuring device section near its operation section so that signals output from the transmitter can be efficiently radiated in the air without installing a specific antenna outside the casing, and without degrading reliability of data transmission and operability of the measuring device section itself.